Note: Descriptions are shown in the official language in which they were submitted.
~13~000 ,~
! ....
.....
. ~ ~
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~ ,.......
. ' . .
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-1- 43-4505A -'''
CONCENTRATED FIRE RETARDANT COMPOSITIONS ' i'
BACKGROUND OF THE INVENTION ''''
Field of the Invention '''
The present invention relates to lmproved
chemical compositions useful for preventing and con- -'
trolling forest~ rangeland and brush fires. More
specifically, this invention relates to concentrated -
retardant compositions which are readily adaptable for -
use in fixed, portable or mobile fire-fighting facilities.
lO These concentrated compositions can be kept separate "'
from the customary dilution water until dispensing becomes ''
necessary at' the time of use. -
Description of the Prior Art --
Forest fires, rangeland fires and brush fires
annually result in the loss of millions of dolIars worth
of timber and other property. Not only is the direct '''
property loss due to such fires catastrophic, but asso-
ciated soil erosion and watershed problems are often of
even greater magnitude. It is important, therefore, to
minimize and control the spread of such fires whenever
possibleO
Known fire-fighting techniques for forest and
- rangelands are widely di~erse. One method employs
physical removal' of the "fuel" (brush, foliage, etc.) from
-25 the path of the oncoming holocaust. Another method applies
a cooling medium, e.g., water or thickened water, directly
:
.
.''':'
i
..
. .
1 131000
on the flames. Still another method employs chem~cal
f~re retardants which modify the fuel to make it less
flammable. Often all three of these methods are
employed, essentially simultaneously, in order to con-
tain and control a single situation. ~arious methodsof distributing fire-fighting solution, including
direct spraying and aerial dropping, have been employed.
Aerial dropping is often advantageous to more quickly
reach areas which are not easily accessible.
According to U.S. Patent No. 3,553,128 issued
January 5, 1971, there are two broad kypes of fire
retardants commonly employed in fighting forest, range,
grass and brushland wildfires. These fire retardants
can be classified as '~short-term" and "long-term"
retardants. Short-term retardants, as defined in U.S.
3,553,128, rely upon the water they contain to retard
combustion. They are thus effective only until their
contained water evaporates. Long-term retardants con-
tain, in addition to water~ a chemical that effeckively
retards ~laming combustion even after any contained
water has evaporated. The latter type, which can be
employed ror fire prevention as well as to contain
existing fires, are relevant to this invention.
At present, the most commonly used long-term
retardant chemicals-are ammonium salts of phosphoric
acid and sulfuric acid. In some cases, fertilizer
solutîons containing mixtures of ammonium ortho-, pyro-
and polyphosphates are utilized~
In addition to the active fire retardant
chemical, most retardant compositions contain a number
of other components which are varied dependlng upon the
recommended usage and mode of application. ~hese other
components are employed either to enhance the overall
performance or the ease of using the composition. ~or
example, additives are frequently employed to alter the
rheological properties of the composition in such a manner
" ,, ~
3~
--3--
that the fire retardant will exhib-~t lmproved free-fall
characteristics when dropped from high altitudes; will
adhere to the wildland fuels in thicker layers, and will
flow in such a manner as to cover all surfaces of the
fuel~ Other additives found to be of benefit include
dyes or pigments to improve vlsibility, a variety of
materials which reduce the metal corrosivity of the
composition, and bactericides which improve liquid
storage stability. The desirability and level of usage
Of these additives depend on the particular fire retard-
ant employed, the utili.zation of the product (prevention
or control) and the type of apparatus used to deliver
the material to the fuel. Formulations containing such
additives are disclosed in U.S. Patent No. 3,409,550; U.SO
Patenk NoO 3~585,135; and.U.S. Patent No. 3,634,234.
In practice, concentrated (solid or liquid) fire
retardant compositions are generally diluted with water
prior to application. The term dilution encompasses both
dissolving and dispersing of solids in water~ The fire
retardant properties of long-term retardants are
dependent on the chemicals present, and the dissolution
media has an insignificant in~luence on these properties.
It does, on the other hand, contri~ute to the ease of
handling the product and improves its distribution on
and adherence to the fuel. The concentration of the
- dilute retardant solution may be varied depending on the
needs of the fire situation and the per~ormance charac-
teristics of the delivery apparatus. Concentrated ~ire
retardant compositions are disclosed in U.S. 3,730,890
and U.SO 3,809g653.
In addition to performance, two other factors
associated with con.centrated fire retardant compositions
are o~ extreme importance, namely, logistics and ease
and simplicity of handling and dilution. Product logis-
tics relate to the weight and volume of ~ire retardantconcentrate which must be utilized per unit volume of
1~3~000
dilute solution. Dilution water is generally available
in close proximity to the fire. The smaller the volume
and weight of concentrate, the easier it becomes to ''
supply the needed vo'lume of dilute product at the fire f
site at the time that it is required. In 'this respect,
diluent-~ree products have significant logistical
advantages over concentrates containing diluentsO For 5.
example, dry powder'products have improved logistics
in comparison with concentrated water solutions in
which the water diluent has no significant influence
on product performance. On the other hand, the handling,!`'.'.'
sto~age and dilution with water of dry powders usually '
requires somewhat more sophisticated equipment in compari- -'
son with liquid concentrates.
C'onsiderable effort has been expended in recent~'
years to reduce the complexities of dry powder usage. '-
Exemplary of such efforts is UOS. Patent No. 3,777~775,
issued December 11, 1973~ which discloses a portable
semibulk handling system for reducing the problems
20 associated with the use o~ dry-powder chemical retard- i'
ants. While these efforts have been highly successful,
further improvements are desirable in certain situations. ~-:
For example, the weight and volume o~ mixing equlpment
,
required to use dry powder retardants on small wildland
fire vehicles can restrict the amoun~ of fire-fighting
chemical which can be transported to the fire. '
Whether to use plain water or chemical retardant
solution often depends upon the severity and danger of
the particular fire. Ideally, the operator should have
the option of incorporating chemical retardants into a
water stream on a "demand basis"~ In this context, a
"demand basis" refers to a scheme in which the concen-
trated chemical retardant is kept separate from the
dilution water until actual application on the fire line ''
is desired. Thus, the decision whether to apply plain
water or chemical retardant solution, and the concen-
_, ~
., .
,, .
1131000
--5--
tration o~ that solution on the fire, can be made atthe application sike with no contamination of one with
the other. Storage and stability problems associated
with advance preparation of chemical retardant solutions
5 could thereby be circumvented. Handlin~ and transport ~
difficulties could thereby be minimized. t'.
It is an ob~ect o-~ the present invention, there-
~ore, to provide novel highly concentrated forest and
rangeland fire retardant compositions. Since the compo~
sitions o~ this invention are highly concentrated fluids,
they combine the logistical advantages of dry powder
systems with the ease and simplicity o~ handling and -
dilution Or less concentrated liquid systems. These
novel compositions are adaptable to usage in a 7Idemand~
15 manner. Such concentrated compositions would be advan- -
tageous in groùnd or aerial application of fire retardant
solutions~ They ~ould be especially appropriate for
mobile operations such as exemplified in present day
wildland fire vehicles.
Other objects of the present invention will
become apparent from a consideration of the ~ollowin~
description and claims. -
SUMMARY OF THE INV~NTION
The concentrated ~ire retardant compositions o~
~his invention comprise:
a) a solid component selected ~rom
the group consisting of monoammonium
orthophosphate 7 diammonium orthophosphate;
monoammonium pyrophosphate; diammonium
pyrophosphate~ triammonium pyrophosphate;
tetra-ammonium pyrophosphateg ammonium ,;
polyphosphates, ammonium-alkali metal
mixed salts o~ ortho-, pyro- and poly- .
phosphates, ammonium-alkaline earth metal
mixed salts o~ ortho-, pyro- and polyphos-
phates; ammonium sul~ate; ammonium sulfamate,
~3~6~0
--6--
urea phosphatej phosphoramides and
mixtures thereof,
b) a liquid component which con-
tains a material~selected from the group
consisting of phosphorus-containing acids
and ammonium-containing salts thereof~ ;
ammonium polyphosphates, phosphorus-
containing estersg ammonium su]fate,
ammonium sulfamate and mixtures thereof; and
c) a rheological property control
agent which imparts thl~otropic flow
properties to the composition;
wherein the weight percentages of said components in the
compositions are from about 20 percent to about 70 percent -
for the solid component, from about 20 percent to about
70 percent for the liquid component and from about 0.1
to about 10 percent for the rheological property control
agent, and the weight percent of P205 and S03, taken
collectively~ in said compositions is at least Llo percent.
The concentrate compositions of this invention,
which eould be considered pastes or slurries, were found
to exhibit easily extrudable fluid rheological properties.
These concentrates can be readily transported and stored
near the fire base and can easily be mixed with water,
if desired, on demand. Exceptionally high concentrations
of flame retardant chemicals are obtained with the
concentrated compositions of this in~ention. This inven~
tion thus provides compositions with a combination of
iogistical and handling features heretofore not achieved
with compositions known in the art.
DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS
The solid component (a) of the compositions of
the present invention is selected from the group con-
sisting of monoammonium orthophosphate; diammonium
orthophosphate~ monoammonium-pyrophosphate; diammonium
- pyrophosphate, triammonium pyrophosphate, tetra-ammonium
pyrophosphate; ammonium polyphosphates;~ammonium~alkali
.,
" - I'
113~00
metal mixed salts of ortho-, pyro--and polyphosphates,
ammonium-alkaline earth metal mixed salts of ortho-, :
pyro- or polyphosphates; ammonium sulfate; ammonium
sulfamate; urea phosphate; phosphoramides and mixtures
5 thereof. The phosphorus-containing materials are pre- ~
ferred. ~-
The materials which can be employed as compo-
nent (a) are well-known in the art. Those skilled in
the art will recognize that these materials can be -
derived from phosphorus- or sulfur-containing acids
by reaction with an appropriate cation. In general,
the cations in these cPmpounds are thermally fugltive
(volatile)3 which means that they volatilize or degrade
to volatilizable fragments at temperatures below the
ignition temperature of forest a~d rangeland fuels.
Typical mixed cation salts include NH4MHPO
4)2 4~ NH4M2P04~ NH4M3P207 and (NH~)2M2p2o7
wherein M is an alkali metal cation, i.e., a metal from
Group Ia of the Periodic Table of the Elements, e.g.,
sodiurn or potassiumO Magnesium an~onium phosphate
(MgNH4Po4-6H2o) exempli~ies an alkaline earth metal
amrnonium orthophosphate. Alkaline earth metals are
well known to be metals of Group IIa of the Periodic
Table of the Elements.
The ammonium polyphosphates utilized in this
invention can be prepared in general by heat treating
phosphoric acid or ammonium phosphates such as diammonium
phosphate with a combined ammoniating and condensing
agent such as urea. These amrnonium polyphosphates are
30 of the formula !~
H(n m)+2(NH4)mPn3n+1
wherein n is an integer having an average value between
3 and about 800, n has an average value between 0.7 and
about 1.1, and m has a maximum value equal to n~2. The
physical characteristics of these ammoniurn polyphosphates
and the various processes for preparing them are
-8-
described in U.S~ Patent 3~397,035 dated August 13, 1968.
The average value of n in the foregoing formula is
determined by the end group titrakion method [Van ~azer
et al, Anal. Chem. 26~ 1755 (1954)]. When n is below r::
20 the ammonium polyphosphates are substantially water
soluble, and much less soluble products result when n
is greater than 20.
The liquid component (b) of the compositions
of this invention contains a material selected from the -
group consisting of phosphorus-containing acids and
ammonium-containlng salts thereof, ammonium polyphosphates,
phosphorus-containing esters, ammonium sulfate, ammonium
sulfamate and mixtures thereof. These materials thus
provide a liquid component which contains fire retardant
15 chemicals. Typically, component (b) will be an aqueous -
solution containing the aforementioned materials, although
liquids other than water may be employed in component (b).
It is desirable to maximize the amount of the aforemen-
tioned materials in the liquid component to provide high
levels of fire retardant chemicals in the compositions of
this invention. The phosphorus-containing materials are
preferred for use in the compositions of this invention. :
The phosphorus-containing acids which may be
present in component (b) are typically provided by
employing commercially available aqueous phosphorus-
containing acid solutions. Preferred acid solutions are
those corresponding to the highest concentration of P2O5.
One such preferred acid is orthophosphoric acid at 85
percent concentration in water. This form is available
commercially as a colorless oil, miscible with water,
and having a speci~ic gravity of 1.7 at room temperature.
Also preferred are phosphoric acid solutions containing
condensed moieties which result in very high P2O5 contents
for such solutions, for example, such solutions are known
to have P2O5 weight percents from about 76 to about 83
percent. Orthophosphoric acid with greater dilution,
..
;
_9_
i.e.~ in concentration less than 85 percent, is also
uselul ~n preparing component (b) of these compositions.
The liquid component (b) may also be obkained -
by employing typical liquid ammonium phosphate fertilizer
5 solutions which have long been available commercially. -
One such commercially available material is designated
in the fertilizer trade as '~8-24-o!' and contains 8 weight
percen~ nitrogen in the form of the ammonium ion and 24
weight percent phosphorus expressed as the anhydride
P2O5. ~he composition and concentration of "8-24-0"
can be varied as desired by the addition of ammonia,
water and/or phosphoric acid. Solutions such as "8-24-01'
are obtained by neutralization of phosphoric acid having t
strengths between about-25 and 71 weight percent phos-
15 phorus (as P2O5) with anhydrous or aqueous ammonia.
The heat o~ neutra~ization can be removed by indirect
heat exchange or by flashing a portion of the water
content of the neutralization zone. The reactants are
admixed in suitable proportions to obtain an aqueous
20 fertilizer solution having a pH bekween about 5.1 and
about 7.8j preferably the fertilizer solution pH is r
between about 6.o and 7.8.
Many similar liquid fert-ili%er solutions can
be employed to obtain the liquid component (b) of the
25 compositions of the present invention. Exemplary of
such liquid fertilizers, commonly referred to as liquid
ammonium polyphosphates but more properly described as
polyammonium phosphates, are fertilizers known as 10-34-0
11-37-0, 13-39-0, 12-40-0 and 13-42-0. The numerical
30 designatlons for these compounds represent the weight
percent nitrogen; phosphorus and potassium, respectively,
present in the fertilizer solutions, wherein phosphorus
and potassium are given in terms of P2O5 and K2O,
respectively.
The liquid component (b) o~ the concentrated
fluid compositions of this invention may comprlse water-
3L~3~L~0~3 ~
-10- 1
soluble phosphate esters having liquid properties in .
their pure form. Phosphate ester fluids have long been
known as fire resistant hydraulic fluids having satis-
factory lubricating characteristics. Typical of such
liquid phosphate esters are trialkyl phosphates. The
latter can be branched-chain alkyl esters of phosphoric ,.
acid hav~ng a low pour point and-high viscosity index.
Usually the alkyl groups will contain 2 to 20 carbon
atoms each~ may be alike or diffèrent~ and are obtained
by a synthesis route employing the "oxo" process. The
total number of carbon atoms in a typical trialkyl
phosphate fluid useful in the present invention would
be.in the range of ~ to 32~ ~
Certain triaryl phosphates, such as tricresyl '
phosphate, are other phosphate esters which have the
necessary liquid properties to satisfy the requirements .
of the solution..phase for the concentrates of the
present invention. .
Solutions of monoammonium phosphate or dlammonium
phosphate are yet other examples of materials which may
be employed to obtain component (b). Those skilled in
the art will recognize other salts of phosphorus- ,.
containing acids which are sufficie.ntly soluble in water
or other liquids. which may be employed in component (b).
The ammonium polyphosphates which may be
employed in component (b) are the previously described
ammonium polypho.sphates wherein n is generally less
than 20.
The materials present in.component (b) may be
mixtures of the various aforementioned materials.
~arious materials which may be present in the liquid
component (b) may also be present in a solid state as
component (a).
The concentrated fluid compositions of this
invention also compr~se a rheological property control
agent which imparts thixotropic flow properties to the
~L~3~
composition. The presence of this component, designated
component (c) herein, allows for the achievement of a
viscosity for the concentrated composition which is
suitable for easily transporting and diluting with
water, and at the same time results in compositions
after dilution containing suitable rheological properties
for placement and formation of the fire retarding composi-
tion upon the fuel surface. Concentrated fluid composi-
tions containing materials corresponding to surprisingly
high levels of P2O5 and/or SO3 in the compositions are thus
obtained. The use of such agents is described in U.S.
Patent No. 4,101,485 issued to D. L. Brooks et al on
July 18, 1978.
While not to be construed in a limitiny sense,
preferred rheological property control agents for use
herein are cross-linked interpolymers of C2-C~ olefins
and maleic anhydride. Particularly effective results
have been achieved with ethylene maleic anhydride inter-
polymers.
Preparation of cross-linked ethylene maleic
anhydride interpolymers is described in U.S. Patent
Nos. 3,073,805 and 3,165,486. Thus, many cross-linking
agents are known for use in the production of cross-
linked C2-C4 olefin maleic anhydride interpolymers.
Vinyl esters of crotonic acid such as vinyl crotonate
have found considerable utility in this regard - see
U.S. Patent No. 3,165,486.
Another preferred type of rheological property
control agent for use in the present invention are
galactomannan gums, sometimes referred to as polygalac-
tomannans or polysaccharides. The use of such gums is
described in U.S. Patent No. 3,634,234. Particularly
preferred for use in -the present invention are derivatized
guar gums, more particularly carboxyalkyl ethers and
, . . .
,~ ~"s
~3~
-12-
hydroxyalkyl ethers of guar gum. ~till more preferred
are hydroxyethyl and hydroxypropyl ethers of guar gum.
The use of ~uch derivatized polygalactomannans is des
cribed in copending Canadian Application Serial No~ 328,346
filed on May 25, 1979.
Other rheological property control agents useful
in this invention are cross-linked polyacrylic acids,
certain natural and modified bentonite clays, cellulose
derivatives such as hydroY~yethyl cellulose and carboxy-
methylcellulose, and the like, so long as they impart
the desired thixotropic flow properties to the composi-
tions of this invention. The desired thixotropic flow
properties will be dependent upon the mode of application
intended for the composition after dilution. For example,
application as a stream or spray from a fire hose requires
a much lower sheared viscosity for the diluted composition
than that required when the diluted solution is applied
by gravity dropping from an aircraft.
Although its presence is not necessary in the
concentrates of this invention, a humectant can often
provide improved handling and other properties. Typical
humectants which may be employed are polyhydric alcohols
such as ethylene glycol, diethylene glycol, polyethylene
glycols, propylene glycol, glycerine, dipropylene glycol,
sorbitol, mannitol and the like.
The humectant is present, if at all, in rela-
tively small amounts to avoid undesirable reduction of
available fire retardant chemicals in the finished
concentrate composition. For optimum fire-fighting
efficiency, it is desirable to maximize the presence of
the fire retardant chemical, typically the P2O5.
To illustrate the slurry concentrate compositions
of this invention, numerous formulations were prepared and
tested. Viscosity, pH and corrosion properties were
observed on various concentrates within the scope of
this invention. Surprisingly high concentration of flame
3~0
-13-
retardant chemicals (e.g., P2O5) were maintained in the
final concentrate formulations thus assuring superior
fire fighting capabilities when employed in admixture
with water ~or dispensing from application equipment.
The following Example I illustrates the prepara~
tion of a concentrated fluid cornposition of this inven- ~
tion containing a solid component, a liquid component, ~`
and a viscosity control agent.
All parts and percentages in any of the following
examples~ unless otherwise speci~ied, are by weight.
Viscosity determinations were at 22C~ and, unless indi-
cated as having been obtained with a Brookfield viscometer,
were made according to hSTM D-1823~66 (Reapproved 1972)
entitled "Standard Methods o~ Test for Apparent Viscosity
of Plastisols and Organosols at High Shear Rates ~y
Castor-Severs Viscometert!.
EXAMPLE I
.
To 133 grams of diammonium phosphate (solid
component) was added 66 grams of 10-34-0 liquid fertilizer j:
solution (liquid component) and 0.4 grams of a vinyl
crotonate cross-linked ethylene maleic anhydride copolymer
(rheological property control agent). The components were
vigorously mixed together at room temperature to obtain a i~
concentrated fluid containing 52.5 percent by weight P2O5.
The viscosity of the fluid concentrate was 103000
centipoise.
The following Example II illustrates a fluid
concentrate composition of the present invention employing
a humectant (polyhydric alcohol).
3o EXAMPLE II r
To 134 grams of diammonium phosphate was added
46 grams of 10-34-0 liquid fertilizer solution, 3.5 grams
o~ a propylene oxide derivative of guar gum and 8 grams
of sorbitol (humectant)~ The resulting concentrate
contained 45 percent by weight P205! The fluid concen-
trate had a viscosity greater than 52,000 centipoise and
.. ~.
-14-
exhibited adequate fluid flow propertles. After dilu-
tion to a 20 percent solution, the composition exhibited
a Brookfield viscosit~ of 150 centipoise and a pH of
8.4.
The follo~ing examples illustrate formulations !l
and properties of additional ~luid concentrate composi- t~.''
tions within the scope of the present invention. The
same procedure was followed in each of the following ~,
Examples as set forth in Examples I and II above. l~
EXAMPLE III l:
Solid - 127 grams of diammonium
phosphate
Liquid - 64 grams of 10-34-0 liquid
fertiliæer solution
Rheological Property
Control Agent ~ 9 grams of a propylene
oxide derivative of --
guar gum
The resultant fluid concentrate had a viscosity
greater than 52,000 centipoise and exhibited adequate
fluid flow properties. The composition contained 44.5
percent by weight P205. After dilution to a 20 percent
solution the composition had a Brookfield viscosity of
2063 centipoise and a pH 7.6.
EXAMPLE IV
Solid - 132 grams monoammonium
phosphate
Liquid - 44 grams 10-34-0 liquid
fertilizer solution and
24 grams 85 percent ortho-
phosphoric acid
Rheological Property
Control Agent - 0.4 gram vinylcrotonate
cross-linked ethylene
maleic anhydride
copolymer `
The resultant fluid concentrate exhibited
adequate fluid flow properties and contained 55.8 percent E
P2O5 and had a p~ 1.4.
.. ,--~ fl
.. ~ ~
-15- l
EXAMPLE ~ Ir:
Solid - 66 grams of diammonium
phosphate and
76 grams of monoammonium ~:
phosphate ~L
Liquid - 29 grams of 10-34-0 liquid
fertilizer solution and
29 grams of water
Rheological Property
Gontrol Agent ~ 1 gram of a vinylcrotonate
cross-linked ethylene
maleic anhydride copolymer
The resultant fluid concentrate contained 45.8
percent by weight P205 and exhibited a Brookfield
viscosity of 3000 centipoise prior to further dilutlon.
EXhMPLE VI !.
Solid - 161 grams of a triammonium
hydrogen pyrophosphate -
(NH4)3H P207 - containing
61.4 percent water solu-
ble P205.
Liq1lid - 39 grams of water
Rheological Property 1-
Control Agent - 1 gram of a vinyl crotonate
cross-linked-ethylene
maleic anhydride copolymer
- resin
The resultant fluid concentrate contained 49
percent P205 and exhibited a Brookfield viscosity of
1128 centipoise and a pH of 6.7.
EXAMPLE VII
Solid - 79 grams of monoammonium
phosphate and 90 grams -
of diammonium phosphate
Liquid - 31 grams of water
Rheological Property
Control Agent - 0.6 gram of a vinyl crotonate
cross-linked ethylene
maleic anhydride
copolymer t'
The resulting fluid concentrate contained 48.5
percent P205 and exhibited a Brookfield viscosity of
2000 cent~poise.
~ ~ .
,, ~
-16-
EXAMPLE ~III ..
Solid - 292.5 grams diammonium ::
phosphate
Liquid - 99.4 grams of 10-34 0
liquid fertilizer ~
Polyhydric - 38.3 grams sorbitol ~-
Alcohol i:.
Rheological Property .
Control Agent ~ 7.5 grams derivati.zed r!
polysaccharide of ....
the guar gum type
The resulting fluid concenkrate contained 43.1 E
percent P205 and had~adequate fiuid flow properties~ A E.
20 percent aqueous solution thereof exhlbited a pH of
8.4 and a viscosity of 150 centipoise as measured with '-.
a Brookfield No. 4 Spindle. ..
EXAMPLE IX .
:
Solid - 292.5 grams diammonium -
phosphate ...
Liquid - 127.8 grams 10-34-0 fertillzer ..
solution and 18.3 grams ..
of 85 percent concen- .
trated phosphoric acid .:
Rheological Property . -.
. 25 Control Agent - 7.5 grams derivatized ,:.
polysaccharide of the -
- guar gum type
The resulting concentrate contained 49 percent .-.
P205 and had.adequate fluid flow properties. A 20 per- .
30 cent-aqueous solution thereof had a Brookfield viscosity ..
of 65 centipoise and a pH of 6.9. ..
EXAMPLE X .. :
Solid - 292.5 grams diammonium .:.
phosphate `.
Liquid - 99.4 grams 10-34-0 ferti- .
lizer solution~ 55.0 --
grams 85 percent ,-.
phosphoric acid
Rheological Property
Control Agent - 7.5 grams derivatized -.
polysaccharide of the ~:
guar gum type
: . .
....
..
,, ''' ' .
-17-
The resulting concenkrate contained 50.1 percent ~:
P2O5 and had adequate fluid ~low propertiesO A 20 per-
cent aqueous solution thereof had a Brookfield viscosity ~
of 55 centipoise and a pH of 6.5. l:
From the above Examples, therefore, it can be
seen that the fire retardant fluid concentrate composi~
tionsof this invention are exemplified by numerous
different concentrations and combinations of the respec- ~
tive ingredients~ Furthermorea the fluid concentrate ir
compositions can be prepared according to numerous con-
venient proceduresg including simply blending or mixing
together o~ the appropriate amounts of the respectlve
ingredients. A flow conditioner such as tricalcium
phosphate or magnesium carbonate can be advantageously
incorporated in the solid phase to facilitate handling
during processing.
Other additives such as corrosion inhibitors,
antifoaming agents, coloring agents and the like may
be conveniently incorporated into the fluid concentrates
20 of this invention. -
Weight concentration of the solid component (or
components) within the total composition may vary within
rather broad limits depending upon the parkicular appli-
cation involved. Thus, the solid component (a) will
usually comprise from about 20 percent to about 70 percent
by weight of the composition. Preferably, the solid
comprises from about 30 percent to about 60 percent by
- weight of the composition.
Weight concentration of the liquid component (b)
in the fluid concentrate composition is often about the
same as that of the solid phase~ It is to be understood,
however, that the liquid component concentration may be
allowed to vary as dictated by the conditions of appli-
cation and the mixing or blending equipment to which the
35 fluid concentrate is ultimately expected to be exposed. !:
Typically, the liquid component comprises from about 20
-18-
to about 70 percent by weight o~ the composition,
pre~erably about 30 to 60 percenk. Liquid component
(b) typically contains from about 10 percent to about
85 percent by weight P205 and S03, taken collectively~ k
preferably about 30 percent to about 85 percent.
The rheological property control agent is
typically present in a concentration from about 0.1
percent to about 10 percent by weight of the total
composition. c
It is desirable to ad~ust the concentrations
of materials in the compositions of this invention to
achieve maximum concentrations o~ the ~lame retardant
chemicals (measured, for example, as P205) and at the
same time achieve acceptable rheological and other
properties. Flame retardancy is imparted by the phos-
phorous or sulfur-conta~ning chemicals and the weight
percentage o~ ~lame retardant chemicals is hereln
measured by the weight percentage of the total P205 and -
S03 corresponding to the materials present in the total
compositionO It is to be understood that although P205
and S03 are considered collectively ~or this purpose,
we do not mean to imply that both must be present. It
should be apparent that either may be present alone~ or
both may be present in the compositions of the present
invention. In general, the compositions contain a
minimum of about 40 percent by weight of P205 and S03,
taken collectively. Preferred compositions contain a
minimum of about 45 percent by welght of P205 and S03,
and a minimum o~ about 50 percent is even more preferred.
The maximum concentration of flame retardant chemicals
achievable is limited only by the materials themselves
and the requirement that the composition exhibit
acceptable fluid properties.
The concentrated compositions of this invent~on
are generally diluted with water prior to application in
the field. Dilution may be varied depending on the needs
.
. ,. ~ .
,. . .
~L~3~
--19--
of the fire situation. Typically ~he concentrated
compositions are diluted to about 10 percent to about ~:
25 percent by weight solutions thereof.
The novel compositions of this invention
5 provide concentrated fluids with exceptionally high
levels of flame retardant chemicals. There is thus F
provided compositions with a combination of the afore-
mentioned handling advantages of a fluid and the
logistical advantages of highly concentrated compo-
10 sitions. Compositions with these combined features have
hereto~ore not been disclosed in the art.
While this invention has been described with
respect to specific examples and embodiments, it is to
be understood that the invention is not limited thereto
15 and that it can be variously practiced within thé scope
of the following claims~
..
. . .
.
